Mobile segmented cylindrical pontoon structure



June 6, 1961 P. J. RUSH 2,987,024

MOBILE SEGMENTED CYLINDRICAL PONTOON STRUCTURE Filed May 11, 1959 5 Sheets-Sheet 1 June 6, 1961 P. J. RUSH 2,987,024

MOBILE SEGMENTED CYLINDRICAL PONTOON STRUCTURE Filed May 11, 1959 5 Sheets-Shet 2 PAUL J. RUSH INVENTOR.

ATTORNEY June 6, 1961 J, U 2,987,024

MOBILE SEGMENTED CYLINDRICAL PONTOON STRUCTURE Filed May 11, 1959 5 Sheets-Sheet 3 PAUL J. RUSH INVENTOR.

ATTORNEY June 6, 1961 P. J. RUSH 2,987,024

MOBILE SEGMENTED CYLINDRICAL PONTOON STRUCTURE Filed May 11, 1959 5 Sheets-Sheet 4 PAUL J. RUSH INVENTOR.

BY MAW ATTORNEY June 6, 1961 P. J. RUSH MOBILE SEGMENTED CYLINDRICAL PONTOON STRUCTURE Filed May 11, 1959 5 Sheets-Sheet 5 Ema I I I I :EIIIILE ATTORNEY Navy Filed May 11, 1959, Ser. No. 812,563 Claims. (Cl. 114-.5) (Granted under Title 35, US. Code (1952), see. 266) This invention many be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a mobile, segmented, cylindrical pontoon structure which may be used as a causeway, bridge, or floating pontoon barge. When used as the latter, a source of mobility such as an outboard type of internal combustion engine or other type of marine engine with propelling means may be furnished.

While this invention will be described with a military connotation, it is to be understood that its structure may be used for commercial and industrial purposes as well as those military purposes particularly set forth.

Amphibious operations on certain beaches have been hampered by the fact that tidal mud flats extended from the waters edge for considerable distances before firm soil conditions were found. During these operations, combat vehicles that were brought to the shore by landing craft or by pontoon causeways or barges were immobilized in the soft soil of the beaches. In some places, While the soil at the beach-head was firm enough to support vehicular trafiic, the areas behind the beach-heads were found to be of swampy character, impassable for man or vehicle.

In studying the requirements of means to resolve the problems posed by the foregoing landing conditions, it was soon recognized that the answer could be supplied by a light-weight, easily-moved and easily-installed structure capable of supporting combat vehicular traffic from ship to shore and across unstable terrain including streams and inlets. The structure should be capabel of supporting traflic loading of at least 60 tons. The structure has to be capable of being carried in an amphibious landing craft, delivered to the beach from the sea, and rapidly installed in areas of swamp, mud, soft sand, volcanic ash, or other unstable low load-bearing capacity soils.

The general object of my invention, therefore, is to provide a highly mobile pontoon structure that may be easily moved through water or over land and installed with facility to construct a causeway over unstable terrain. By combining one or more of my mobile pontoon structures, a causeway of any length can be constructed.

Another object of my invention is to provide a highly mobile pontoon structure that may be used to construct a bridge across a narrow body of water for the passage of vehicular traffic.

A further object of my invention is to provide a highly mobile and easily transported pontoon structure that may be transformed into a power driven barge for transporting freight of any sort between ship and beach-head. Where power drivers suitable for the purpose are not readily available, the barges are adapted to be towed by other vessels such as tugs or landing craft.

Other and further objects and advantages of my invention will be appreciated in conjunction with the following description and drawings wherein like reference characters used throughout the various views denote like parts and wherein: I

FIGURE 1 is a view in perspective of my mobile, segmented, cylindrical pontoon structure;

FIG. 2 is a view in perspective illustrating my pontoon structure as installed for use;

FIG. 3 is a view in perspective of the end towing arrangement;

FIG. 4 is a perspective, partly sectional view of the basic segmented pontoon structure; and

FIGS. 5, 6, 7 and 8 illustrate certain details of my invention. I

With reference to the figures and particularly FIG. 1, my mobile, segmented, cylindrical pontoon structure 10 comprises a plurality of segmented pontoons 12 assembled in the form of a mobile cylinder with end towing structures 14 and towing yoke 16. Towing chain bridle 18 is provided for use in towing the pontoon structure 10 in the water when end structures 14 and yoke 16 have been removed. Also, when the pontoon structure has been opened out into a floating barge, chain bridle 18 may be utilized for towing it and may be further used in anchoring the pontoon structure to the shore .or connecting it with another pontoon structure.

Referring to FIG. 4, the basic segmented pontoon structure 13 consists principally of four angle irons 20 to which are secured at least six transverse bulkheads. The intermediate bulkheads or stii'feners 22 are primarily strength members while the other two bulkheads or end plates 24 are for watertight closure purposes. These transverse bulkheads are secured to angle irons 20 by welding or other suitable means. As will be noted, these transverse bulkheads are in the form of segments or seetors, having an outer circular arc 23, radial straight line sides 25, and a chord 26, which chord 26 is perpendicular to the radial bisector (not shown) of circular are 23. The stiifeners 22 are notched at all corners to accept the angle irons 20. These stilfeners 22 are also further notched at the upper corners thereof to accept the strut boxes 30. As shown, angle irons 20 are also notched to accept strut boxes 30. Stiffeners 22, angle irons 20, and strut boxes 30 are joined by welding, brazing, or other suitable means. End plates 24 are notched only at the outboard lower corners for fitting to the outer angle irons 20. The inner angle irons 20 are slightly less in length than the outboard ones and are flush-welded to the inner surfaces of the end plates 24. Each pair of strength bulkheads or stiifeners 22 is joined by an inner reinforcing plate 2.8 which is welded to the inner sides or chords 26 of these stifieners and to the portions of the angle irons 20 situated between the bulkheads 22. These plates 28 are provided to take the load of vehicular traific crossing the pontoon structure and are so positioned with relation to the total length thereof.

The skeleton structure of angle irons 20, transverse bulkheads 22, end plates 24, and reinforcing plates 28 is then completely closed in by straight corrugated metallic sides 32, a circular corrugated outer metallic surface 34, and an inner deck plate 36. These parts are joined by welding, brazing, or other suitable means, to form a complete compartmented, water-and-air tight segmental pontoon. An air fitting (not shown) may be inserted into various locations in deck plate 36 to test the five compartments formed for air and water tightness. The holes for such air test fitting may then be welded over or otherwise plugged up. Suitable threaded plugs could be used so that later air testing could be performed if found necessary or desirable. By assembling these pontoon structures with a number of individual compartments or with the described cellular construction, their water-tight integrity is insured. The volume-to-weight relation is so designed that any two water tight compartments in each segmental pontoon is sufficient to retain flotage.

Inner deck plate 36 is provided withthree span plate pad eyes 38 which may be welded thereto. Two of these pad eyes 38 are located at the corners of the deck plate along one edge thereof while the third pad eye is located in the geometric center of the deck plate. These pad eyes are used for removably securing span plate 40 in an inverted position to the deck plate 36, as shown in FIG. 4. Wedges 39, which may be of metal or wood, are used in conjunction with pad eyes 33 to so secure the inverted span plate to the deck plate.

Span plate 48 is shown in FIG. 4 in the inverted or carrying position. Its normally lower side (upper side in FIG. 4) is equipped with two pairs of reinforcing channels 42 and two pairs of turnbuckle strut storing plates 44. Only one pair of each is shown in FIG. 4, but it is to be understood that another pair of each are located symmetrically with respect to the lower or left hand end of span plate 40 which has been omitted. It should be noted that channels 42 are located over the central portion of reinforcing plate 28. These reinforcing channels 42 and storing plates 44 may be welded or brazed to the span plate 40. Storing plates 44 are provided for conveniently carrying the turnbuckle struts 46. The turnbuckles 47 are turned until the turnbuckle T-bolts '48 take up against the storing plates 44 and the struts 46 are hold firmly in place. Span plate 40 is further equipped with three positioning clips 50 (lower clip not shown in FIG. 4) which are located along one long edge thereof opposite to the edge having the elongated holes 41 which are formed in span plate 40 to receive the span plate pad eyes 38. An additional central hole 41 is provided in span plate 40 to receive the central pad eye 38.

Double hinge pad eyes 52 are secured by welding to one of the lower or outer angle irons 20 and are located, as shown in FIG. 4, at the connection point between a stiifener 22 with the same angle iron 20. A corresponding single hinge pad eye 54 is welded to the opposite lower or outer angle iron 20 also at the connection points of the stiifeners 22 and that angle iron 20 as shown in FIGS. 1 and 6. These hinge pad eyes, when so used as in Figs. 1 and 6, are joined by a bolt or toggle pin 53 to form the hinged connection between adjacent segmental pontoons.

End plates 24 are provided with a single, outwardly extending, handling pad eye 56 which is welded thereto in the upper left hand corner formed between one of the sides 25 and the inner chord 26 (FIGS. 1 and 2). While this pad eye could be located at any convenient place under chord 26, it is preferably located at one upper or inner corner or the other so as to be strengthened by the angle iron 20 which is welded to the inner side of the end plate 24 at those points. The use of these handling pad eyes 56 will be described later.

Strut boxes 30, shown in FIGS. 2, 4, 5, and 7, may be castings or may be built up, as shown, for ease of welding, and are so formed, as best shown in FIG. 5, to accept the turnbuckle T-bolts 43. While the construction of this strut box 30 is clearly shown in FIG. 5, it is made up of a short section of angle iron 31, with side plates 33 and bar stops 35. The receptacle formed between the vertical portion of angle iron 31, side plates 33 and bar stops 35 is designed and adapted to accept the T-head of the T-bolts 48.

The foregoing description has completely delineated the basic construction member or segmental pontoon 12 with its span .plate 40 in position as shown generally in FIG. 4. In assembling the roll or the complete cylindrical structure, less the towing arrangement, six of these basic members are laid side-by-side, the hinge pad eyes are aligned and the hinge toggle pins or hinge bolts are inserted. The structure is then rolled together and the last pairs of hinge pad eyes are aligned and the hinge bolts inserted. The.

cylindrical roll is then completely assembled and is ready for the addition of the towing arrangements 14 and 16.

The towing arrangements consist of the end towing structure 14 and the towing yoke 16. As shown in FIGS. 1 :and 3, towing structure 14 comprises a built up spoke 60, a balancing rod 64, a pair of locking rods 66, and a securing chain 68.

The built up spoke 60 consists of a main channel structure 61 having two end plates 62 welded thereto. These end plates 62 are provided with apertures 63 which are adapted to receive handling pad eyes 56. Plates 62 also carry locking rod receptacles 65 which are angularly disposed therewith and are adapted to receive and guide the locking bars through the handling pad eyes. Spoke 60 carries a securing chain 68 which may be hooked into an eyelet 67 secured to balancing rod 64. Obviously, this securing chain 68 is for the purpose of retaining the locking rods in the locking rod receptacles, thus locking yoke 60 to end plates 24 and handling pad eyes 56. Spoke 60 also carries journal 69 which is a short piece of tubing or pipe welded to the central portion of spoke 60.

Balancing rod 64 is formed from bar metal and has three apertures; the central aperture (not shown) is sufiiciently large for positioning the balancing rod on the journal 69. The end apertures are for the reception of the bent inner ends of the locking rods 66. As previously mentioned, an eyelet 67 is provided for receiving the hooked end of chain 68.

Yoke arm 70 may be of a built-up, box-like construction utilizing two channels, welded together at the webs. At the inner or journal end of the yoke arm, an aperture of sufiicient size is provided for placing the yoke arm on the journal 69. The outer end of the yoke arm is provided with gussets and means of attachment to the generally tubular construction comprising the towing yoke 16. Yoke arm 70 is provided with a roller 71 on its inner side for properly spacing the ends of the segmental pontoons from the yoke arm, thus preventing any of the projections from the end plates 24 or the end towing structure 14 from fouling the yoke arm 70.

The towing yoke 16 is constructed as shown in FIG. 1, in a generally triangular trussed form with the necessary auxiliary struts, trusses, and gusset plates. The lateral corners are firmly secured to the outer ends of the yoke arms 70. A ball and socket hitch 72 may be provided at the outer apex corner of the towing yoke 16.

In attaching the towing rig to the cylindrical pontoon structure, the end towing structure 14 is assembled loose- 1y on the inner ends of the two yoke arms '70. The

balancing rod is turned counterclockwise so that locking ends of the locking rods '66 are disposed in the inner portions of the locking rod receptacles '65. In this position, the locking ends are clear of the apertures in end plates 62. The spoke 60 is placed over diametrically opposite handling pad eyes; any diametrically disposed pair of pad eyes may be used. The length of journal 69 is suflicient so that there is sutlicient play to enable the corresponding parts to be simultaneously positioned at both ends of the cylindrical pontoon roll. Then the balancing rod 64 is turned clockwise forcing the locking rods through the pad eyes and into the outer receptacles, thus securing the spoke 60 to the pontoon roll.

Chain 68 is then hooked into eyelet 67 and the locking rods are prevented from moving out of their locking receptacles and the handling pad eye. With both end structures in position, spacer collars 73 are installed over the journal 69 outboard of yoke arm 70 and the assembly is held in place on journal 69 by the end or locking bolt 74. Spacer collar 73 is provided to act as a bearing between yoke arm 70 and bolt 7 4 since the journal 69, which new functions as a stub axle, turns with the roll pontoon and the yoke arm is stationary in a substantially horizontal position.

The mobile, segmented, cylindrical pontoon structure as described above is now ready to be transported by towing over land or through the water. It may be lifted from dock or barge to ship and from ship stowage tobarge ordock orbe thrown or lowered into :the water.

When the cylindrical roll or cylindrical pontoon structure is towed or moved to a position of use, the towing mately 60.

structures are removed in the reverse order of their attachment as set forth above. Succinctly, bolts 74 and collars 73 are removed. Chain 68 is unhooked. Balancing rod 64 is turned counterclockwise, withdrawing locking rods 66 from the handling pad eyes, and releasing spoke 60. The whole towing structure may then be completely removed and the cylindrical pontoon stands alone ready for further conversion to the actual use.

To open up the roll to the configuration shown in FIGS. 2, 7, and 8, any hinged joint may be disconnected by removing the hinge bolts or toggle pins. The top joint may be opened, or more conveniently a joint in the side nearest the ground or the surface of the water, wherever the roll may be for its intended use as causeway, bridge, or floating barge. The roll is then unrolled until the segmental pontoons have assumed a more or less horizontal configuration. At this point, the span plates 40 are in inverted position as shown in FIG. 4. The turnbuckle struts are removed from their storing plates 44 and are placed into their corresponding strut blocks 30 as shown in FIG. 7. These turnbuckle struts are adjusted to the degree of compression required. For normal use over level swampy terrain or in the water, these struts may be adjusted so that the angle between adjacent sides of the end plates and stilfeners is approxi- Where the terrain is not level, this angle may be varied within a few degrees as may be necessary.

With the turnbuckle struts in place, span plate 40 is freed from the span plate pad eyes and turned over. Span plate clips 50 are inserted under the edge of the deck plate of the next adjacent pontoon and the other edge of the span plate is lowered onto the same end pad eyes from which it had just been removed. The wedges 39 are replaced and the span plate is securely held in position to form a runway or bridging portion between two adjacent pontoons. Pockets for the reception of span plate positioning clips 50 are formed where the valleys in the corrugated sides 32 meet and are welded to the underside of deck plate 36. The function of reinforcing channels 42 which are carried by the span plate is now obvious. These channel reinforced portions are now in line with the reinforcing plates 28, hence the load-bearing portions of the structure are completely aligned and are as contiguous as is possible with this type of mobile structure.

The procedure set forth above as to the positioning of one set of turnbuckle struts and one span plate may be repeated until the unit of six segmental pontoons is converted into a rigid 4-trussed configuration suitable for use as a causeway, bridge, or barge. The extra span plate may be used as a ramp, may be used to connect up one unit with another one, or may be laid aside for use as a spare. Obviously, as many units as are available or desired may be connected up in series.

In the practical use of my invention, the mobile, segmented, cylindrical structure has been constructed of six segmental pontoons assembled into a cylindrical roll of six feet in diameter and a width of thirteen and one-half feet. The unit weighed 6000 lbs., was readily mobile over any sort of ground and floated one third submerged in water. This segmented cylinder opened to form a 4- trussed structure 13 /2 feet wide and 18 feet long. Ten of these basic units were joined to form traflic ways of 180 feet in length. These trafiic ways, which were emplaced on very low bearing capacity soil at the rate of 90 feet per hour, sustained traflic and static loadings of 60 tons. The structures when assembled as floating pontoon bridges at the rate of 130 feet per hour sustained traflic and static loadings of 9 tons. When used as selfpowered floating pontoon barges in a deep still water area, structures made from these cylindrical segmented pontoon units carried loadings up to 14 tons and were maneuverable at a speed of 3 knots.

In the segmental pontoons used in the above construction, the stifleners or bulkhead strength members 22 were 2 feet apart. The reinforcing plates 28 were slightly more than 2 feet in length and were on 7 foot centers. This created a traflic bearing roadway with a minimum width of 5 feet and a 9 foot maximum width.

While the preferred embodiment of my invention discloses the use of six segmental pontoons arranged in a mobile, cylindrical structure, it is to be understood that any number of segmental pontoons can be used. It would appear, however, that for practical reasons, a minimum of six pontoons should be used. While the radial depth of the segmental pontoon structure as actually used was approximately 18 inches, this depth may vary subject to the volume-to-weight ratio necessary to insure a reasonable flotation. Other modifications of my invention may occur to those skilled in the 'art. Removable rubber tires may be supplied to the structure when in cylindrical form. These tires, solid or'inflatable, may be used to protect the cylinder when being towed over land, may increase flotage, and may act as bumpers when the cylinders are being towed in the water or are being hoisted to and from the transport means. It is intended, however, that all such modifications would fall within the spirit of my invention and the scope of the appended claims, wherein I claim:

1. A mobile, segmental pontoon structure suitable for the construction of causeways, floating bridges, or floating barges comprising, in combination:

a plurality of segmental pontoons adapted to be rigidly assembled into a cylindrical structure having a hollow polygonal core and adapted to be rotatably moved from one location to another over land or water, each of said segmental pontoons comprising a longitudinally extending water-and-air tight compartmented structure having four longitudinally extending side plates, a pair of transverse end plates and a plurality of transverse inner bulkheads joining said side plates, said end plates and said bulkheads being in the formof a segmental sector having an outer circular are side, two radial sides and an inner chordal side, said chordal side being perpendicular to the radial bisector of said outer circular are side, said longitudinally extending side plates including an outer curved plate conforming to the circular arc defined by the outer side of said end plates and inner bulkheads and three substantially planar plates, all of said plates being secured to and joining corresponding sides of said end plates and inner bulkheads, two inner longitudinal edges defined by the meeting of said radial side plates and said inner chordal side plate, two outer longitudinal edges defined by the meeting of said radial side plates and said outer circular are side plate, a plurality of hinge means positioned along said outer longitudinal edges, and a plurality of strut receiving means positioned along said inner longitudinal edges;

towing means removably attached to the ends of said cylindrical structure for rotatably moving said structure; and

means intermediate the ends of said pontoons for assembling said plurality of segmental pontoons into a rigid trussed horizontal structure having an upper substantially planar horizontal surface.

2. A mobile segmental pontoon structure as claimed in claim 1 wherein said means intermediate the ends of said pontoons include a plurality of removable adjustable strut means rigidly connecting the inner longitudinal edges of adjacent pontoons.

3. A mobile segmental pontoon structure as claimed in claim 1 wherein said plurality of segmental pontoons are rigidly assembled by means of a plurality of corresponding hinges having removable hinge pins, a portion of said plurality of hinges being placed on each outer longitudinal edge of said segmental pontoon whereby, when said corresponding hinges are aligned and said hinge pins are placed in said aligned hinges, each pontoon 4. A mobile segmental pontoon structure as claimed in claim 1 wherein said means intermediate the ends .of said pontoons include detachable span plates adapted to extend from the inner edge of one pontoon to the inner edge of the next adjacent pontoon, said span plates being equal in length to said pontoon, whereby said span plates and the inner chordal side plates of said pontoons establish an upper substantially planar horizontal surface.

5.. A mobile segmental pontoon structure as claimed in claim 1 wherein said towing means includes end towing structures adapted to be detachably secured to the ends of said cylindrical structure, each of said end towing structures comprising:

a spoke;

cally disposed pontoon end plates;

5 axle being substantially aligned with the longitudinal axis of said cylindrical structure.

References Cited in the file of this patent UNITED STATES PATENTS 1,618,401 Baer Feb. 22, 1927 2,365,446 Barton Dec. 19, 1944 FOREIGN PATENTS 264,872 Germany Sept. 29, 1913 

